Method for demolishing a consolidated and hardened iron ore powder body contained in a hold of an iron ore carrier

ABSTRACT

A method of demolishing a consolidated and hardened iron ore powder body contained in a hold of an iron ore carrier, which comprises the steps of: placing at least one mechanical member in the hold of the iron ore carrier, before the iron ore in a slurry state is charged into the hold; loading the iron in a slurry state into the hold; and causing the mechanical member to move relative to the iron ore body in which the member is buried, at the time of unloading the iron ore which has already been consolidated and hardened.

United States Patent [1 1 Asai et al.

METHOD FOR DEMOLISHING A CONSOLIDATED AND HARDENED IRON ORE POWDER BODY CONTAINED IN A HOLD OF AN IRON ORE CARRIER Inventors: Koetsu Asai, Chiba; Nobuyuki Imanishi; Terutoshi Yamada, both of Kobe, all of Japan Assignees: Kobe Steel, Ltd., Kobe; Mitsubishi J ukog'yo Kabushiki Kaisha, Tokyo, both of Japan Filed: Aug. 7, 1973 Appl. No.: 386,328

Foreign Application Priority Data Aug. 9, 1972 Japan 47-79591 US. Cl 214/152; 214/14; 214/15 R; 214/17 R Int. Cl 1363b 27/24 Field of Search 214/17 R, 152, 14, 15 R, 214/15 C, 15 B,12,13,17 D

[451 July s, 1975 2,522,466 9/1950 Schneider 214/15 C 2,576,620 11/1951 Martin 214/17 R X 3,121,500 2/1964 Langen 214/17 R 3,606,036 9/1971 Beebe ct 214/14 FOREIGN PATENTS OR APPLICATIONS 1,290,084 2/1969 Germany 214/15 C Primary Examiner-Frank E. Werner Attorney, Agent, or Firm-Oblon, Fisher, Spivak, McClelland & Maier [57] ABSTRACT A method of demolishing a consolidated and hardened iron ore powder body contained in a hold of an iron ore carrier, which comprises the steps of: placing at least one mechanical member in the hold of the iron ore carrier, before the iron ore in a slurry state is charged into the hold; loading the iron in a slurry state into the hold; and causing the mechanical member to move relative to the iron ore body in which the memher is buried, at the time of unloading the iron ore which has already been consolidated and hardened.

12 Claims, 10 Drawing Figures PNEHTEHJUL @1975 3.8935.

SHEET 3 [1F 3 METHOD FOR DEMOLISHING A CONSOLIDATED AND HARDENED IRON ORE POWDER BODY CONTAINED IN A HOLD OF AN IRON ORE CARRIER BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method for demolishing a consolidated and hardened iron ore body consisting of fine powder and contained in a hold of an iron ore carrier at an unloading harbor, and more particularly to a method for demolishing the same when using a socalled wet-loading and dry-unloading system in such an iron ore carrier.

2. Description of the Prior Art Before proceeding with the description of the present invention, it may be of assistance for better understanding of the feature of the invention to give the detailed description of the background of the so-called wet loading and dry-unloading system for use in transporting iron-ore in a slurry state from a mine via ocean to a refinery, including the use of an iron-ore transport ship or carrier.

Heretofore, there have been proposed two types of such transportation systems, i.e., one is called a dryloading and dry-unloading system, and the other is referred to as wet-loading and wet-unloading system.

Iron-ore as used herein refers to a magnetite of a lower iron content, which is supplied in fine powder after being crushed and dressed by a known method.

The size of the aforesaid fine powder is 44p. which usually occupies 80% of the total amount of the iron ore.

This kind of iron-ore, because of its very fine size and poor water permeability, incurs to the industry a number of troublesome and hence uneconomical problems in surface transportion (land and sea transportion).

For simplicity of the description, the disadvantages or problems associated with the above two transportion systems will be enumerated below according to the types of such systems;

a. Dry loading and dry-unloading system The system has long been practiced, in which ironore is transported through land transportation such as trucks or railroad from a mine to a shipping harbor, where a huge ore transport ship or carrier such as of 160,000 ton load displacement is loaded with such dry ore by means of belt conveyors.

When the ore carrier arrives at an unloading harbor, such dry ore is unloaded by means of a crane.

The disadvantages of this system are as follows:

i. There results an extemely high transportion expense because of the use of land transporation such as trucks or railroad.

ii. There are required large scale harbor facilities, be cause of the huge ore carrier. Accordingly, the natural conditions of the harbor are predominate factors in the solution of the problems. This results in the land transportation expense occupying a majority of the total transportation expense.

b. Wet-loading and wet-unloading system This system is proposed to solve the problem of the high transportation expense required for transporting iron-ore from a mine to an ore carrier. In this system, the iron-ore fine powder is mixed with water and a pipe line is laid from a mine to a shipping harbor, said pipe line, if required, being extended to the offing for loading the carrier with iron-ore in a slurry state. This provides a very simple and economical facility for the intended purpose, thereby reducing such transportation expense to a great extent. However, the disadvantages thereof offset the above benefit, despite the convenience of the transportation facility. Those disadvantages are as follows:

i. A large scale reservoir or pond near the shipping harbor is required for storing a great amount of ironore in a slurry state for subsequent loading, whereas the simple land-piling of iron-ore in the former system is possible. This in turn requires a broad site for such reservoirs.

ii. At the unloading harbor, there is required a large scale dehydrating facility for the bulky iron ore in a slurry state. This requires the same scale of harbor facility and unloading equipment as those used in the former system, and thus leads to a duplicate investment.

iii. In general, the iron ore in a slurry state cannot meet the demand of iron in quantity, thus necessitating the combined use of a dry ore. Accordingly, there necessarily leads to the provision of storing equipment for both types of iron ore.

iv. During the transport of an iron-ore carrier, there occurs gravity consolidation and hardening of the ironore in a slurry state loaded in a carrier. This unfavorable phenomenon is an extremely troublesome experience with the transportation of slurry ore. More particularly, once the iron-ore is loaded in a hold of a carrier, the iron-ore particulates beginning with sedimentation at a relatively high rate, while being accelerated due to the pressure of gravity of the upper layer of slurry, with the result that the water content of the ore body is reduced from 30 to 40% at the time of loading to about 14%. As the time goes on, the slurry in the hold of the carrier is further consolidated and hardened as a result of vibration in the carrier. As a result, the water content in the ore body is reduced to about 7 to 8%. This value is naturally dependent on the time period of the navigation, ranging from 8 to 10% as an average. The ore body thus consolidated and hardened is very stable in shape and therefore such consolidated ore body may not crumble even if it remains in the form of a vertically extending wall along the sidewalls of the hold of the carrier, although it may be demolished by driving therein a tool having a sharp edge.

Such gravity consolidated and hardended ore body may be again restored to a slurry state by spraying it with water under pressure to transport it to a refinery a long distance from the unloading harbor. However, this attempt results in extremely higher expense, for transportation facilities with considerable difficulties and thus is impractical.

Accordingly, it has been desired to have a novel system utilizing the steps of wet-loading and dry-unloading of the consolidated and hardened ore body in and from a hold of a carrier, thereby achieving an efficient, time and labor saving unloading operation. However, this method further dictates the necessity for a grab-bucket having improved grabbing or unloading capability. In other words, as stated earlier, after navigation for a long period of time, the slurry body is not only consolidated and hardened but also presents a flat top surface of considerable hardness like the interior of the ore body. Accordingly, to use a grab-bucket having flat mating edges, there arise difficulties, because of extremely great resistance of the solidified ore body. It

follows then that it is desirable to have a grab-bucket having improved grabbing capability.

In such a wet-loading and dry-unloading system, particular difficulties are experienced with the demolishing of an iron ore body which remains in a thick wall or cliff form in contact with the inner walls of a hold of the iron ore carrier, after the central portion of the iron ore of a consolidated and hardened body in the hold has almost been removed therefrom by using known means such as a grab-bucket.

Usually, such means involves the use of an operator or operators who have to work inside the hold to supplement the operations of mechanical means. This is not only dangerous but also presents poor efficiency for the operation.

SUMMARY OF THE INVENTION Accordingly, it is a principal object of the invention to provide a method for demolishing a consolidated and hardened iron ore powder body remaining as a thick wall in a hold of an iron ore carrier, which method presents a simple but highly efficient demolishing operation without resorting to the use of operators inside the hold of the iron ore carrier.

It is another object of the invention to provide a method for demolishing such an iron ore powder body, which method is applicable to an ordinary type of iron ore carrier without modifying the construction of the hull of the iron ore carrier.

Briefly stated, the present invention provides a method for avoiding the drawbacks of the conventional art, which method comprises the steps of: placing at least one mechanical member such as a flexible wire or expansible bag in the hold of an iron ore carrier, before the iron ore in a slurry state is charged in the hold; loading the iron in a slurry state in the hold; and causing the member to move relative to the iron ore body in which the material is buried, at the time of unloading the iron ore which has already been in a consolidated and hardened state due to the dyhydrating operation and/or sedimentation during transport. The wording, to move relative to the iron ore body as used herein implies the upward movement of wires being pulled in the iron ore body or the expansion or contraction of bag means buried inside the iron ore body, for the purpose of demolishing a consolidated and hardened iron body.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a transverse cross-sectional view of a hold of an iron ore carrier embodying the present invention, in which a length of chain is buried in the consolidated and hardened iron ore body;

FIG. 2 is a transverse cross-sectional view of a hold of an iron ore carrier embodying the present invention, in which lengths of wires having a plurality of anchors tied thereto are buried in the consolidated and hard ened iron ore body;

FIG. 3 is a transverse cross-sectional view of a hold of an iron ore carrier embodying the present invention, in which a plurality of wires are placed in spaced relation in the vertical plane;

FIG. 4 is a plan view of a hold of an iron ore carrie embodying the present invention, in which a plura ity of lengths of wire or chain are laid either in a longitudinal or a transverse direction in a horizontal plane;

FIGS. 5 and 6 are transverse cross-sectional views of a hold of an iron ore carrier embodying the present invention, in which a plurality of bag means are located along the vertical inner walls of the hold;

FIG. 7 is a transverse cross-sectional view of a hold of an iron ore carrier embodying the present invention, in which another modification is indicated; and

FIGS. 8, 9 and 10 show various configurations and arrangements of expansible bag means placed inside the hold of an iron ore carrier.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, wherein like reference characters designate identical or corresponding parts throughout the several views and more particularly FIGS. 1 through 4 cover the first type of embodiments of the present invention, in which lengths of wire or chain are used as flexible lines, while FIGS. 5 through 10 refer to the second type of embodiments of the invention, in which a plurality of bag means are used instead of the flexible lines of the first type of embodiments for the same demolishing purpose.

Referring now to FIG. 1, which shows the transverse cross-sectional view of an iron ore carrier, there is shown a length of chain 3 which has been laid along and in contact with the inner walls of a hold 2, before the iron ore is charged into the hold in a slurry state. One end of the chain 3 extends beyond one edge of a hatch coaming to a position on an upper deck 5, where the chain is firmly secured, while the other end of the chain 3 extends beyond the opposite edge of the hatch coaming for winding on a machine 6 positioned upon the upper deck 5.

With this arrangement, due to the dehydration of slurry iron ore through the bottom of the hold 2 and the sedimentation thereof, the iron ore in a slurry state becomes dried, in a consolidated and hardened state, when the iron ore carrier arrives at the unloading harbor, with the chain being buried in the iron ore body. When the chain 3 begins to be wound at a winding machine, the iron ore body surrounding the chain 3 will be broken or demolished, because of the upward movement of the chain 3 therethrough, thereby presenting the iron ore in a suitable condition for unloading. In the next stage, the iron ore will be unloaded with ease by means of a conventional grab-bucket.

FIG. 2 refers to another embodiment of the invention, in which a length of wire 8 having a plurality of anchors 7 tied thereto is used in place of the chain 3 of FIG. 1. One end of the wire 8 extends beyond one edge of the hatch coaming for firm attachment to the upper deck, while the other end of the wire 8 extends beyond the other edge of the hatch coaming for winding on a machine located on the upper deck of the carrier.

Like in the previous embodiment, when the wire 8 begins to be wound at the winding machine, the iron ore in a consolidated and hardened state may be bro ken or demolished due to the upward movement of the wire therethrough. In this case, however, the provision of a plurality of anchors 7 tied up to the wire will accel crate the demolishing operation of the iron ore body, thereby increasing the efficiency of the unloading operlOl'l.

A plurality of chains or wires of this kind may be used in case the use ofa single line of wire or chain is not desirable because too great a tension may be applied thereto. In addition, the directions of wires or chains may be transverse or longitudinal with respect to the carrier, or a plurality of wires or chains may be placed in spaced relation one from the other in a vertical transverse plane.

FIG. 3 shows such an embodiment of the invention, in which chains 80, 8b are placed in spaced relation to each other in a vertical transverse plane. in operation, the uppermost line of wireor chain 80 is first wound at the winding machine to cause the upward movement thereof for demolishing the consolidated and hardened ore body in the hold, followed by the winding of the second upper wire or chain 3b, and the same continues for the lower lines of wires in the iron ore body.

As is clear from the foregoing, this obviates the use of excessively great tension, i.e., the tension required for the demolishing purpose being divided uniformly.

FIG. 4 shows a still further embodiment of the invention, in which chains are laid in a network, as shown. in this case, a plurality of chains or wires 3p are provided for being wound at a winding machine, such that uniform demolishing forces may be applied to the iron ore body with increased demolishing efficiency. Furthermore, the chains or wires of the network, as shown in FIG. 4, may be spaced from each other in a vertical plane as in the case with FIG. 3, for improving the demolishing efficiency of the iron ore body contained in the hold of a carrier.

The winding machine for use in winding lengths of wires or chains is preferably placed on the upper deck as shown in FIG. l and FIG. 2. However, a mooring machine on board the carrier may be used in place of such a winding machine.

in case too great a tension is required for a single line of wire or chain or in case the reaction thereof is desired to be borne by a construction other than the hull of the carrier, then an unloader on land may be used for pulling the wires or chains.

As is apparent from the foregoing description, there is required only a simple means for demolishing the iron ore body in an efficient manner, while necessitating no modification of the hull of the carrier in using flexible wires or chains. Furthermore, the facilities such as a grab-bucket or other unloading equipment may be used in tact.

FIGS. 5 through ll) show the second type of embodiments of the invention. FIG. 5 shows the transverse cross-sectional view of an iron ore carrier, in which most of the central portion of the ore body is unloaded by means of a grab-bucket, leaving the iron ore body in a thick wall form along the inner walls of the hold. Shown at l is a high pressure hydraulic pump, at 2 pressure-resisting piping, at 3 an adjusting valve, at 4 expansible bags which are placed along the inner walls of the hold, at 5 a supporting wire for suspending the bags 4 from the upper edge of the hold, at 11 a water discharge pump and at 13 a hook, to which the supporting wire is secured. An air compressor or high pressure hydraulic pump 1 is located inside the carrier, being connected via the pressure resisting piping 2 to the expansible bags. incorporated in the piping is the adjusting valve 3 which is adapted to adjust the flow rate of fluid that is flowing through the pressure=resisting piping 2. The expansible bags 4 are located along the inner walls of the hold 14, being suspended by a supporting wire from the hook id. The pressure=resisting pipe 2 extends through the wall of the hold to the expansible bags t for connection thereto.

in case water is used as a fluid, the water is fed under pressure from a high pressure pump 1 through the pressure resisting pipe 2 and then through the adjusting valve 3 into the expansible bags 4 for the expansion of the bags 4. At this stage, a grab-bucket 6 is in a standby position above the hold and may be used for unloading the iron ore from another hold. When the expansible bags are expanded, the iron ore body 7 remaining as a thick wall or in cliff form along and in contact with the inner walls of the hold will be gradually broken into blocks as the bags are being expanded, and then collapsed onto the bottom of the hold as shown in FIG. 6. The adjusting valve will be closed at the completion of the collapse of the iron ore body toward the center of the hold, followed by gradual opening of the valve 3' to thereby discharge the water from the expansible bags 4 by means of the water discharge pump ii. in contrast thereto, in case air is used as a fluid. the water discharge pump 11 is not required, but the mere opening of the discharge adjusting valve 3' can discharge the air from the bags. The expansion and contraction of the expansible bags 4 may be carried out for each wall of the hold or may be carried out for all the walls of the hold simultaneously.

FIG. 7 shows another embodiment similar to that shown in FIG. 5, the difference being that the pressureresisting piping 2 runs from the top of the hold down to the bags 4 for connection thereto. However, the operation of the bag system in this embodiment is the same as in FIG. 5 and FIG. 6.

While the description has been given with reference to the various embodiments. it is also possible that the expansible or contractible bags as well as the pressurercsisting piping are installed on the carrier side. while the means for feeding fluid into said expansible bags and the means for discharging the fluid therefrom are located on the land side. Furthermore, it is possible that the expansible bags are expanded within the hold, before the slurry state iron ore is charged therein. and then the fluid is discharged at the time of unloading the iron ore from the hold, thus demolishing the consolidated and hardened iron ore body remaining along and in contact with the inner walls of the hold.

The expansible or contractible bags are made of a synthetic composite sheet in which the core sheet of synthetic fibers are coated with synthetic resin sheet. having a pressure resistance of an order of 5 lag/cm.

FIG. 8 shows one example of the arrangement of expansible bags and the configuration thereof. As shown. the bag body 4 is divided into several sections or compartments extending in a vertical direction, each being independent from the other, but using a common pressure source outside the bag body. The water or air under pressure is fed through the adjusting valve 3 to the bags 4.

FIG. 9 shows another arrangement of the bags as used in the present invention, in which the pressureresisting piping extends through the side walls of the hold. FIG. 10 shows a still further example of the ar= rangernent and configurations of bags embodying the present invention, the bag body being separated inde pendently one from the other. while the compressed air or water is fed from above down to the bags. Throughout the examples of the bag bodies as shown in FIGS. 8 through ll], each of the bag bodies is divided into several independent sections or compartments, each hsv= ing a respective adjusting valve, such that the iron ore body remaining along and in contact with the inner walls of the hold may be demolished in any desired sequence or even simultaneously, thus facilitating the demolishing operation of the iron ore body. With the arrangement, like the previous type of flexible lines, an operator need not work inside the hold during the phase of demolishing the iron ore body remaining as a thick wall or in cliff form in the hold, thereby presenting safety to operators with the accompanied increased efficiency. In addition, the installation of such bag means and pipings is quite simple and thus requires no skill nor the need to modify the construction of the hull of the carrier for installing such equipment.

It will be understood that the above description is merely illustrative of preferred embodiments of the invention. Additional modifications and improvements utilizing the discoveries of the present invention can be readily anticipated by those skilled in the art from the present disclosure, and such modifications and improvements may fairly be presumed to be within the scope and purview of the invention as defined by the claims that follow.

What is claimed as new and desired to be secured by Letters Patent of the U.S. is:

l. A method for demolishing a consolidated and hardened iron ore powder body for the purpose of facilitating unloading the same from a hold of an iron ore carrier, comprising the steps of:

placing a plurality of mechanical members within a planar array in said hold of said iron ore carrier, before the iron ore in a slurry state is charged into said hold;

loading the iron ore in a slurry state into said hold;

permitting said iron ore to consolidate and harden so as to form a dry and hardened iron ore body; causing said mechanical members to move relative to the iron ore body in which said members are buried, at the time of unloading said iron ore from said carrier, thereby demolishing the iron ore body in a consolidated and hardened state; and

unloading said demolished iron ore body from said carrier while in said dry state.

2. A method according to claim 1, wherein said mechanical members are lengths of flexible lines.

3. A method according to claim 2, wherein said flexible lines are chains or wires which are placed along or in parallel to the inner surfaces or walls of said hold, whereby, when said chains or wires are wound, said chains or wires will be pulled upwardly through said consolidated and hardened iron ore body, thereby demolishing the same.

4. A method according to claim 2, wherein said flexible lines have a plurality of anchors tied thereto.

5. A method according to claim 2, wherein a plurality of said lines are placed inside said hold in a transverse and longitudinal direction of said carrier.

6. A method according to claim 5, wherein a plurality of said lines are placed in spaced relation from each other in a transverse vertical plane of said carrier.

7. A method according to claim 2, wherein said lines are wound upon a winding machine mounted on an upper deck of said carrier, with the other ends thereof secured in a position on said upper deck thereto.

8. A method according to claim 2, wherein said lines are pulled upwardly by means of an unloader located on land.

9. A method according to claim 2, wherein said lines are pulled by a mooring machine on board said carrier.

10. A method according to claim 1, wherein said mechanical members are expansible or contractible bag means.

11. A method according to claim 10, wherein a plurality of said expansible or contractible bag means are placed along and in contact with the inner surfaces of said hold, whereby the consolidated and hardened body contained in said hold may be demolished by causing said bag means to be expanded or contracted, with a fluid introduced into or discharged from said bag means.

12. A method according to claim 10, wherein said bag means are made of a composite sheet material which consists of synthetic fibers, forming a core material, and a synthetic resin coated thereon. said composite sheet material being capable of withstanding a pressure of an order of 5 Kg/cm.

* F l i 

1. A method for demolishing a consolidated and hardened iron ore powder body for the purpose of facilitating unloading the same from a hold of an iron ore carrier, comprising the steps of: placing a plurality of mechanical members within a planar array in said hold of said iron ore carrier, before the iron ore in a slurry state is charged into said hold; loading the iron ore in a slurry state into said hold; permitting said iron ore to consolidate and harden so as to form a dry and hardened iron ore body; causing said mechanical members to move relative to the iron ore body in which said members are buried, at the time of unloading said iron ore from said carrier, thereby demolishing the iron ore body in a consolidated and hardened state; and unloading said demolished iron ore body from said carrier while in said dry state.
 2. A method according to claim 1, wherein said mechanical members are lengths of flexible lines.
 3. A method according to claim 2, wherein said flexible lines are chains or wires which are placed along or in parallel to the inner surfaces or walls of said hold, whereby, when said chains or wires are wound, said chains or wires will be pulled upwardly through said consolidated and hardened iron ore body, thereby demolishing the same.
 4. A method according to claim 2, wherein said flexible lines have a plurality of anchors tied thereto.
 5. A method according to claim 2, wherein a plurality of said lines are placed inside said hold in a transverse and longitudinal direction of said carrier.
 6. A method according to claim 5, wherein a plurality of said lines are placed in spaced relation from each other in a transverse vertical plane of said carrier.
 7. A method according to claim 2, wherein said lines are wound upon a winding machine mounted on an upper deck of said carrier, with the other ends thereof secured in a position on said upper deck thereto.
 8. A method according to claim 2, wherein said lines are pulled upwardly by means of an unloader located on land.
 9. A method according to claim 2, wherein said lines are pulled by a mooring machine on board said carrier.
 10. A method according to claim 1, wherein said mechanical members are expansible or contractible bag means.
 11. A method according to claim 10, wherein a plurality of said expansible or contractible bag means are placed along and in contact with the inner surfaces of said hold, whereby the consolidated and hardened body contained in said hold may be demolished by causing said bag means to be expanded or contracted, with a fluid introduced into or discharged from said bag means.
 12. A method according to claim 10, wherein said bag means are made of a composite sheet material which consists of synthetic fibers, forming a core material, and a synthetic resin coated thereon, said composite sheet material being capable of withstanding a pressure of an order of 5 Kg/cm2. 